Most motor vehicles comprise a bonnet or hood in which the upper air inlet grille is formed. This air inlet grille is generally positioned between the front headlamps. The bumper or fender is positioned below the aforementioned air inlet grille. In the event of a frontal impact with a small-sized pedestrian, such as a child, for example, the head of the pedestrian strikes the bonnet, substantially, above the upper air inlet grille. The natural flexibility of the bonnet, which is made of sheet steel, is able to absorb part of the impact, through deformation of the bonnet.
However, for the last few years, and for reasons of style, motor vehicles have had very bulky front bumpers. These bumpers comprise a central part which rises up toward the bonnet, between the front headlamps. It is often this part of the bumper which bears the upper air inlet grille. The bonnet itself is shortened and its free edge is situated fairly high up between the headlamps. In the event of a frontal impact with a small-sized pedestrian, the head of the pedestrian strikes not the bonnet but the central part of the bumper. Bumpers of this type are made up of several components which, for functional reasons, are very rigid. Such bumpers can therefore seriously injure a pedestrian, particularly the head of a small-sized pedestrian.